Evaluation of the Moisture Sorption Behaviour of Several Excipients by BET, GAB and Microcalorimetric Approaches

Abstract

Moisture content of solid-state pharmaceutical products is one of the main factors that affect drug stability, therefore suitable sorption studies need to be performed to assure drug quality throughout their shelf life. The Brunauer-Emmett-Teller (BET) and the Guggenheim-Anderson-de Boer (GAB) models are usually used for this purpose. Using gravimetrically obtained data, both methods were applied in the present work to evaluate the sorption characteristics of several excipients. Microcalorimetric analysis was also performed in order to evaluate the interaction between water and the substances. The results of these experiments show excellent agreement between data and the BET model up to 55% RH and the GAB model over the entire humidity range, confirmed by high values of the statistical determination coefficients. Furthermore, microcalorimetric measurements suggested that the hygroscopicity of solid materials could be estimated approximately using this approach.

Cellulose nanocrystal surface functionalization for the controlled sorption of water and organic vapours

“…The enthalpies of immersion thus measured are presented in Table 2, which shows that the order of magnitude of enthalpy was close to what might have been expected for wetting enthalpy, because the samples were not outgassed before measurement which most probably left residual water on the CNC surface. For example, the wetting enthalpy of MCC (Avicel) by water was measured at -3.7 J/g (Douillard and Malandrini 1999), while the immersion enthalpy of Avicel (of approximately -3 J/g) was measured using a comparable method by Roskar and Kmetec (2005). The exothermic immersion enthalpy of CNC in water can easily be explained by the high contact angles and hence the high surface energy of CNC, because of polar interactions and hydrogen bonding.…”

Package Selection for Moisture Protection for Solid, Oral Drug Products

“…The moisture sorption behavior of pharmaceutical solids can be described in terms of parametric models. 42,43 Monolayer adsorption behavior is generally described by the Brunauer-Emmett-Teller (BET) model; however, the more general Guggenheim-Anderson-de Boer (GAB) model is more commonly applicable. 44 The GAB equation can be expressed as follows:…”

De-risking Scale-up of a High Shear Wet Granulation Process Using Latent Variable Modeling and Near-Infrared Spectroscopy

“…Moisture sorption was measured by SGA-100 (VTI Corporation: 7650 West 26 th Ave, Hialeah, FL, USA 33016). For the data analysis of moisture sorption profile, Guggenheim, Anderson, and de Boer (GAB) model [44][45][46][47] was applied to extract suitable thermodynamic property information (see Appendix). The API properties used in this study are shown in Table 1.…”